In order to cool a compressed gas of a high or normal temperature to a lower level than a dry-bulb temperature to remove humidity of the gas for preventing water drops from being condensed in a feeding pipe, a refrigerator has been used.
However, the refrigerator requires a high plant cost and a high power consumption due to necessity of cooling operation by means of a compressor. Further, the refrigerator may often suffer from accidents, such as leakage of a coolant from a heat exchanger pipe, and must be inspected and replaced periodically. Thus, the maintenance and inspection must be carried out very often, resulting in a high maintenance cost.
Accordingly, an object of the invention is to provide a dehumidifier of a compact type, which may efficiently cool a compressed gas of a high or normal temperature by water to a lower level than a dry bulb temperature and thus remove humidity of the gas, without need for a power from a compressor, thereby to save the maintenance cost considerably.